4.8is Air Suspension woes

[EODguy]

Originally Posted by hamza

So I thought this was sorted… garage changed the air bag on the passenger side front a few weeks ago…

Unfortunately it looks like the driver side looks an inch to two or so lower than the passenger side .. so might need to change that too? Odd thing is though, the button to change the ride height isn’t doing anything, it’s not pumping the driver side back up to match when the car starts or anything either.

When I press the button to raise the ride height it just flashes away and nothing happens. No errors on the dash either though.

Any ideas?

Most likely the tank pressure release valve is stuck or the inline equalizing valve (not sure of proper name)

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[andrewwynn]

Originally Posted by hamza

So I thought this was sorted… garage changed the air bag on the passenger side front a few weeks ago…

Unfortunately it looks like the driver side looks an inch to two or so lower than the passenger side .. so might need to change that too? Odd thing is though, the button to change the ride height isn’t doing anything, it’s not pumping the driver side back up to match when the car starts or anything either.

When I press the button to raise the ride height it just flashes away and nothing happens. No errors on the dash either though.

Any ideas?

Scanner situation? You need to read the sensor values and compare. Also; check the lever arms. E53 are notorious for the joints rusting and the arm no longer moving correctly. I've seen them bent like a banana.

Also: the front sensor arm is known to flip to the wrong side at the elbow. Not sure if that's possible on the back. I would check to make sure all arms are the correct orientation.

(The sensor lever needs to be mostly horizontal the arm to the lever mostly vertical)

[hamza]

Originally Posted by EODguy

Most likely the tank pressure release valve is stuck or the inline equalizing valve (not sure of proper name)

Sent from my SM-A730F using Tapatalk

Where are these located and is it something I can check myself or is it a back to the garage job?

[hamza]

Originally Posted by andrewwynn

Scanner situation? You need to read the sensor values and compare. Also; check the lever arms. E53 are notorious for the joints rusting and the arm no longer moving correctly. I've seen them bent like a banana.

Also: the front sensor arm is known to flip to the wrong side at the elbow. Not sure if that's possible on the back. I would check to make sure all arms are the correct orientation.

(The sensor lever needs to be mostly horizontal the arm to the lever mostly vertical)

I don’t have a scanner, maybe I need to buy one I guess?

Would the sensor arms prevent it from inflating all the other corners too when the button is pressed to raise the ride height?

[andrewwynn]

You need a scanner to DIY any bmw.

I have foxwell 510. The 520 is nearly identical.

The more complete system is to install bootleg bmw scanner software on a laptop but I vastly prefer to just hook up a hand held scanner.

The ride height system will disable itself if it finds a fault but you will get the light on the dash in such case.

If you don't have the error light than I suspect one of your arms is bent and sending the wrong signal to the computer.

If that's the case, the crooked look you are having is literally "the new level".

The car has no idea what level is it just knows how far down each corner is supposed to be pushed. If a level sensor is reading the wrong value the car will inflate/deflate each corner until the sensor reads what is programmed to read.

Get a photo of each corner sensor.

If you have one axle air suspension the right front will also have a sensor but I think you said you have a ride level button so you have 2 axle air.

These are from real OEM. The sensor and regulating rods must be in this orientation.

The back ones tend to rust to the point they will no longer swivel and all hell breaks loose. You should remove and refurbish all of them (or replace them if like in my case the ball joints are "made of rust".

[andrewwynn]

When changing an air spring calibration may be needed (also when changing any control arm where the regulating rod is attached).

First get a photo of all four sensors; with the wheels on the best way to do this is borrow a friend's iPhone and FaceTime between them. Mute the sound or you'll have feedback hell. Then use one phone as the ROV and one as the view screen.

Take screen shots from the view screen phone.

[hamza]

Thanks for those tips. Very helpful indeed.

I'm wondering if maybe the garage just put the sensor on one of the wheels (where they replaced the bag) on incorrectly...

Whilst I'm handy enough with a spanner and have most tools (except a scanner!) I no longer have the time to DIY my cars anymore. I don't really have a good specialist to hand either so have just used an honest and fairly reliable local garage who pretty much do what I ask them after talking you knowledgeable chaps!